Objectives: Co-resistance to fluoroquinolones and β-lactams results in treatment complications for uropathogenic Escherichia coli (UPEC) infections. This study aimed to detect the coexistence and co-transmission of plasmid-mediated quinolone resistance (PMQR) and extended-spectrum β-lactamase (ESBL) genes in UPEC from Kolkata, India.
Methods: Escherichia coli was detected biochemically from culture-positive urine samples. Antimicrobial resistance and ESBL production were confirmed by disk diffusion assay. Transfer of PMQR and ESBL genes was performed using azide-resistant E. coli J53 as recipient. PCR was conducted to identify PMQR and ESBL genes, plasmid incompatibility types, insertion sequences, integrons and ERIC-PCR patterns.
Results: PMQR determinants were detected in 50.0% (35/70) of ciprofloxacin-resistant isolates, with ESBL production in 42.9% (15/35) and a β-lactamase inhibitor-resistant phenotype in 51.4% (18/35). The highest co-occurrence (37.1%; 13/35) and co-transmission of aac(6')-Ib-cr with blaTEM, blaCTX-M and blaOXA was observed. Among the conjugal plasmids, replicon types FrepB/FrepB+F1B were predominant, with rare incidences of A/C, N, X, I1, FIIS, L/M and H1. Distribution of integrons and ISEcp1 and IS26, either alone or in combination, irrespective of PMQR and ESBL gene types was observed. Discrete ERIC-PCR profiles indicated that acquisition of PMQR and ESBLs and their dissemination may be attributed to horizontal gene transfer.
Conclusion: This study demonstrates for the first time the risk of co-transmission of fluoroquinolone and β-lactam resistance amongst UPEC from Kolkata, posing a major public-health threat and limiting treatment options. Monitoring at the molecular level is necessary to design appropriate prescription policies to combat the alarming rise in drug resistance amongst these uropathogens.
Keywords: Co-transmission; ESBL; Fluoroquinolone resistance; PMQR; UPEC; Uropathogenic Escherichia coli.
Copyright © 2018 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.